
Gastroesophageal reflux disease (GERD), also known as an acid reflux or heartburn, is a chronic digestive disease. It occurs when the acid from the stomach flows back (reflux) into the oesophagus (food pipe). This acid reflux irritates, and can sometimes damage, the lining of the oesophagus. It can also reach the vocal cords, or even flow back into the lungs.
In normal digestion, the muscular valve between the stomach and the oesophagus (food pipe), known as the lower oesophageal sphincter, opens to allow food to pass into the stomach, and closes to prevent food and acidic stomach juices from flowing back into the oesophagus.
Every once in a while, it is normal to experience acid reflux, where your stomach contents flow back up into your oesophagus. However, if this occurs more than twice a week for a few weeks, it could be a sign of GERD.